Theorem fmptapd 7126

Description: Append an additional value to a function. (Contributed by Thierry Arnoux, 3-Jan-2017.) (Revised by AV, 10-Aug-2024.)

Hypotheses

Ref	Expression
fmptapd.a	⊢ (𝜑 → 𝐴 ∈ 𝑉)
fmptapd.b	⊢ (𝜑 → 𝐵 ∈ 𝑊)
fmptapd.s	⊢ (𝜑 → (𝑅 ∪ {𝐴}) = 𝑆)
fmptapd.c	⊢ ((𝜑 ∧ 𝑥 = 𝐴) → 𝐶 = 𝐵)

Assertion

Ref	Expression
fmptapd	⊢ (𝜑 → ((𝑥 ∈ 𝑅 ↦ 𝐶) ∪ {⟨𝐴, 𝐵⟩}) = (𝑥 ∈ 𝑆 ↦ 𝐶))

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝑥,𝑅   𝑥,𝑆   𝜑,𝑥

Allowed substitution hints:   𝐶(𝑥)   𝑉(𝑥)   𝑊(𝑥)

Proof of Theorem fmptapd

Step	Hyp	Ref	Expression
1		fmptapd.c	. . . 4 ⊢ ((𝜑 ∧ 𝑥 = 𝐴) → 𝐶 = 𝐵)
2		fmptapd.a	. . . 4 ⊢ (𝜑 → 𝐴 ∈ 𝑉)
3		fmptapd.b	. . . 4 ⊢ (𝜑 → 𝐵 ∈ 𝑊)
4	1, 2, 3	fmptsnd 7124	. . 3 ⊢ (𝜑 → {⟨𝐴, 𝐵⟩} = (𝑥 ∈ {𝐴} ↦ 𝐶))
5	4	uneq2d 4108	. 2 ⊢ (𝜑 → ((𝑥 ∈ 𝑅 ↦ 𝐶) ∪ {⟨𝐴, 𝐵⟩}) = ((𝑥 ∈ 𝑅 ↦ 𝐶) ∪ (𝑥 ∈ {𝐴} ↦ 𝐶)))
6		mptun 6644	. . 3 ⊢ (𝑥 ∈ (𝑅 ∪ {𝐴}) ↦ 𝐶) = ((𝑥 ∈ 𝑅 ↦ 𝐶) ∪ (𝑥 ∈ {𝐴} ↦ 𝐶))
7	6	a1i 11	. 2 ⊢ (𝜑 → (𝑥 ∈ (𝑅 ∪ {𝐴}) ↦ 𝐶) = ((𝑥 ∈ 𝑅 ↦ 𝐶) ∪ (𝑥 ∈ {𝐴} ↦ 𝐶)))
8		fmptapd.s	. . 3 ⊢ (𝜑 → (𝑅 ∪ {𝐴}) = 𝑆)
9	8	mpteq1d 5175	. 2 ⊢ (𝜑 → (𝑥 ∈ (𝑅 ∪ {𝐴}) ↦ 𝐶) = (𝑥 ∈ 𝑆 ↦ 𝐶))
10	5, 7, 9	3eqtr2d 2777	1 ⊢ (𝜑 → ((𝑥 ∈ 𝑅 ↦ 𝐶) ∪ {⟨𝐴, 𝐵⟩}) = (𝑥 ∈ 𝑆 ↦ 𝐶))

Syntax hints:   → wi 4   ∧ wa 395   = wceq 1542   ∈ wcel 2114   ∪ cun 3887  {csn 4567  ⟨cop 4573   ↦ cmpt 5166

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1912  ax-6 1969  ax-7 2010  ax-8 2116  ax-9 2124  ax-10 2147  ax-11 2163  ax-12 2185  ax-ext 2708  ax-sep 5231  ax-pr 5375

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 849  df-3an 1089  df-tru 1545  df-fal 1555  df-ex 1782  df-nf 1786  df-sb 2069  df-clab 2715  df-cleq 2728  df-clel 2811  df-nfc 2885  df-ne 2933  df-ral 3052  df-rex 3062  df-rab 3390  df-v 3431  df-sbc 3729  df-dif 3892  df-un 3894  df-in 3896  df-ss 3906  df-nul 4274  df-if 4467  df-sn 4568  df-pr 4570  df-op 4574  df-opab 5148  df-mpt 5167

This theorem is referenced by:  fmptpr  7127  poimirlem3  37944  poimirlem4  37945  poimirlem16  37957  poimirlem17  37958  poimirlem19  37960  poimirlem20  37961